dzhokhar tsarnaev is in serious conditions with gunshot wounds to the head, neck, leg, and hand. he has communicated to investigators by nodding and writing. at his bed side, a court representative says i will ask the doctor whether the patient is alert. the doctor asks, how you are feeling? tsarnaev nods. authorities are convinced the two brothers acted alone. >> i told boston they can rest easily. >> reporter: the affidavit describes the brothers walking through the marathon crowd with knapsacks and then separating. at one point, dzhokhar can be seen slipping his knapsack to the ground. he used his cell phone, then walked away. seconds later, an explosion. and information about a trip to russia last year. a trip that caught the attention of russian authorities who alerted the u.s., tamerlan tsarnaev may have had contact with terrorists. >> yes, he went to chechnya for a couple of days. i don't know where his relatives lived. they were from his father's side. >> reporter: surprised tamerlan had become such a devout muslim. >> tamerlan taught everything to himself. >> reporter: t